Field of the Invention
The present invention relates to a body-warming apparatus for use by a user such as, for example, a diver to maintain body heat during submersion. The portion of the apparatus that provides heat to the user is a heated garment or article worn by or secured to the user. The remaining portion is carried by the user along with other gear.
Background of the Related Art
A diver can remain submerged in water only for as long as he can maintain sufficient body heat to prevent hypothermia. The inability to maintain sufficient body heat can result in shivering, hypertension, tachycardia, tachypnea, vasoconstriction, mental confusion, diuresis and hepatic dysfunction. Severe hypothermia can result in a faltering heart rate, respiratory rate and low blood pressure and even death.
A submerged diver loses heat to the surroundings much more quickly than heat is lost in cold air. A water temperature of 10° C. (50° F.) can result in death in as little as one hour, and can impair motor skills in just minutes without proper maintenance of body heat.
One drawback to the use of conventional body warmers is the production of bubbles. A diver may wish to remain undetectable during a dive, and this is difficult when bubbles are being generated by the diver's equipment and released into the surrounding water. The bubbles migrate to the surface where they can be seen by observers on or at the surface of the water.
Other hostile environments that may require equipment to maintain body heat include environments in which a user is “submerged” in corrosive, poisonous or combustible gas mixtures, or very cold environments that will not tolerate or support an open combustion system. For example, but not by way of limitation, cold gas environs, within a gas storage facility or tank, the vicinity of natural gas or liquefied gas storage or processing tanks or in some areas of a liquefied natural gas tanker. It will be understood that the term “user,” as that term is used herein, may refer to a diver or it may refer to a person that is or will be exposed to environmental conditions in which the body's natural ability to regulate the body temperature is insufficient and in need of supplemental heat for personnel safety.